This invention is directed generally to a raised access floor panel, and more particularly, to a floor panel that has an improved strength-to-weight ratio and compatibility with existing raised access substructures.
Heavy-duty floor panels are commonly used in industrial applications, for example, in clean room environments for making semiconductor chips. Heavy-duty floor panels are required to support heavy static and rolling loads. While heavy-duty floor panels are known in the art, there is a need for floor panels that are stronger and capable of supporting even heavier loads, while at the same time being lighter in weight than conventional heavy-duty panels.
To safely store and ship such heavy-duty floor panels, there is also a need for such a floor panel that can be stacked securely, and preferably without the addition of packing materials between adjacent floor panels. In general, floor panels are stacked face-to-face to prevent damage to the floor panel face. Thus, if more than two panels are to be stacked, understructures of adjoining panels would necessarily contact each other. Conventional floor panels, however, typically have uneven understructures. Thus, it is not possible to securely stack several conventional floor panels without some sort of packing material placed between understructures of adjoining floor panels to make the stack level.
The heavy-duty floor panel of the invention meets these needs by providing a panel that is stronger than, but about the same weight as conventional heavy duty panels. In other words, the invention increases the strength-to-weight ratio of currently available heavy-duty floor panels. Additionally, the heavy-duty floor panel of the invention meets the need of being able to be stacked securely and without the need for packing material placed between adjacent floor panels.
In general, the heavy-duty floor panel of the invention meets these needs by providing an understructure having a unique combination of structural members of variable width and height, thereby reducing the overall weight of the panel yet providing increased strength. The invention also solves the problem of stacking several panels by providing spaced inner and outer contact surfaces of a substantially uniform height, which enables level stacking of panels without the need for additional packing material.
More particularly, and in accordance with one specific embodiment of the invention, a heavy-duty floor panel is provided for use in an elevated floor system. The floor panel has a top, bottom and plurality of sides defining an outer perimeter of the floor panel. A plurality of reinforcing structures may extend from the bottom and be arranged in a pattern to optimize the strength to weight ratio of the panel. The reinforcing structures may include five series of reinforcing structures. The first series of reinforcing structures may have a first, substantially constant height, be disposed adjacent to the outer perimeter of the floor panel, and may have a thickness that varies along their length. The second series of reinforcing structures may have a second, substantially constant height different from said first height, be disposed inwardly from said first series of reinforcing structures, and may also have a thickness that varies along their length. The third series of reinforcing structures may have a third height substantially equal to the second height, and be spaced inwardly from the second series of reinforcing structures. The fourth series of reinforcing structures may extend across the panel between at least two of the second series of reinforcing structures. The fourth series of reinforcing structures also may have a height that varies along their length. At least one of the fourth series of reinforcing structures may have a curved portion connected to at least one of the second series of reinforcing structures to reduce stress concentrations. The fifth series of reinforcing structures may extend between and connect the first and second series of reinforcing structures.
At least one of the first and second series of reinforcing structures may have a thickness greater in its middle than at its ends. The second and third series of reinforcing structures preferably define spaced level, surfaces upon which other panels may be stacked.
The fourth series of reinforcing structures may be arranged in a grid-like pattern forming a plurality of repeating cells, and there may be at least one additional curved reinforcing structure disposed within at least one of the cells. Preferably, the at least one curved reinforcing structure comprises a plurality of curved ribs dividing the cells into four substantially equal quadrants. The height of the fourth series of reinforcing structures may vary between a maximum height at their middle and a minimum at the ends of each of the fourth series of reinforcing structures to form a generally-pyramidal shape with the third series of reinforcing structures. A plurality of perforations may extend through the floor panel, and may be arranged in a repeating pattern defined at least in part by some of the fourth series of reinforcing structures.
The fifth series of reinforcing structures may also have varying height, and may include curved portions connected to at least one of first and second reinforcing structures to reduce stress concentrations. A sixth series of reinforcing structures may extend between the fifth series of reinforcing structures.
The heavy-duty floor panel of the invention preferably is cast from an aluminum alloy.
According to another aspect of the invention, the heavy duty floor panel of the invention may be part of an elevated floor system for supporting access floor panels. The system may include pedestals having a head for supporting at least one of the heavy-duty floor panels, and may be particularly adapted to replace existing floor panels, e.g., by being formed with an appropriately-sized lip at its outer perimeter. The elevated floor system may include at least one stringer disposed between at least two pedestals and adapted to support a ledge formed by the second and fifth series of reinforcing structures of the floor panel of the invention.
According to yet another aspect of the invention, a method of stacking a plurality of heavy-duty floor panels is provided in which each floor panels has a top, a bottom, a plurality of sides, and a plurality of reinforcing structures extending from the bottom that are arranged in a pattern producing outer and inner spaced, stacking surfaces of substantially uniform height. The method includes the steps of placing the top of a first one of the floor panels against the top of a second one of the floor panels and placing the inner and outer spaced stacking surfaces on the bottom of the second one of the floor panels against the inner and outer spaced stacking surfaces on the bottom of a third one of the floor panels. The step of placing the bottom stacking surfaces of the second panel against the bottom stacking surfaces of third panel may be performed without the use of any packing material therebetween.
Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. It is to be understood that the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed.